Of the numerous discrete and separate operations entailed in the manufacture, and specifically the binding, of a hardcover book, "casing-in" is the process in which a book and its hard cover (or "case") are fastened together.
My U.S. Pat. No. 4,091,487, issued May 30, 1978 for a "Method for Binding Books" discloses an important improvement over conventional book binding, wherein the signatures are first collated, the spines or backbones of the signatures are then cut off to provide a single backbone exposing every sheet in every signature, and whose edges can be glued together and to at least one paper cover that will ultimately be glued to the interior surfaces of a conventional hard cover, after the other three edges of the assembled and collated signatures are trimmed.
My U.S. Pat. No. 4,106,148, issued Aug. 15, 1978 for a "Method of Binding Papers", discloses an additional improvement over conventional book binding, wherein notches or apertures are cut into the spines at intervals to permit the flow of adhesive glue well into the backbone of all of the pages in every signature. This method avoids the waste of paper and the extra step of grinding the backbone while still eliminating the even-more-costly step of sewing the signatures.
My co-pending U.S. patent application Ser. No. 145,018 discloses still another method for binding a book wherein the backbone of printed and folded signatures receives a heat activated glue. A short reinforcing cover whose inner surface is also covered with a heat activated glue is applied to the backbone. The outer portions of the short cover are then bonded to the outer pages of the signatures, under sufficient heat and pressure to form a strong bond. A hard cover of suitable size and shape is then glued to the outside of the short cover and the signatures.
The present invention relates to a method for casing-in books which is faster, more economical, and more accurate than conventional casing-in, and which creates a finished hardcover book that is as strong as, or stronger than, books cased-in by the usual methods.
In effect an assembly operation, casing-in uses as raw materials (1) complete books (without hard covers, often referred to as "book blocks"), (2) completed hard covers or "cases", and (3) glue, paste, or some other adhesive to bond the book blocks and cases together. Book blocks and cases are produced in the book bindery, each in a separate and distinct series of operations, prior to casing-in. There are numerous alternative methods and materials that may be employed in both book block-and case productions.
These in-process materials may differ in their appearance or structure. Book blocks, for example, may be bound, inter alia, with adhesives, by needle-and-thread sewing, or mechanically (such as wire-spiral bound or with plastic). Their backbones or spines may be "flat backed" or "round backed", depending upon the shape or configuration of the raw materials, and particularly that of the book blocks. The number and nature of the discrete steps in casing-in may vary in its current art.
Regardless of the types of book blocks or cases used, presently known casing-in is slow and cumbersome, and requires considerable hand labor, requiring four basic steps, i.e.
(1) Glue, paste, or some other adhesive is evenly applied to the outside of both the first and last pages ("endpapers") of the book block. In conventional casing-in equipment, the book block is positioned either manually or mechanically astride a flat, metal, vertical plate called a "wing". The wing then mechanically lifts the book block, drawing it between a pair of rollers that applies the adhesive to the outer endpapers. If the books to be cased-in have a rounded back, a second pair of rollers applies adhesive at the "joints" where the backbone flares out. Finally, if the books are to be "tight backed" (also glued along the spine), still a third application of adhesive is required. PA0 (2) The hard cover, or case, is subjected to heat and pressure at its spine between a male-female set or pair of metal "forming irons" which rounds or curves the cases' spine into conformity with the shape of the book block's spine. In conventional methods, cases are dispensed from a hopper and remain stationary during forming. PA0 (3) The adhesive-coated book block is inserted into the now-formed case in the position in which the two are to be adhered. In prior art equipment, the adhesive application operation and case forming operation are synchronized so the book and cover meet at their respective spines as the book is lifted through the adhesive-dispensing rollers. As the wing continues to rise, the front and back sides of the cover drape around the book block. PA0 (4) The book block and case are pressed together so the glue or paste will bond both together. In some conventional equipment, this step is performed mechanically before the cased-in book is ejected. With other equipment, however, this step must be performed manually by removing and clasping the book block-and-case unit from its wing.
If the now-complete books were permitted to dry as is, they would warp badly. Accordingly, casing-in is immediately followed by a separate and distinct bindery operation called "building-in", in which heat and pressure are applied to the book so it will dry flat.
A number of problems and shortcomings are inherent to the aforedescribed conventional methods for casing-in. In general, conventional casing-in methods are mechanized versions of manual operations, and the equipment used to perform the various steps of casing-in is complex and cumbersome. Book blocks and cases, while being processed, are subject to continuous stopping and starting, and abrupt and awkward movements. This invites questionable and uneven performance, considerable maintenance, slow operation, and recurrent breakdowns, all contributing to high production costs.
Especially in the situation in which adhesive-bound book blocks are to be cased-in, a drying period before casing-in is required to permit the adhesive binding to set. A direct transition from binding to casing-in before the requisite drying period elapses would place undue stress on the adhesive binding, occasioning distortion, mangling, or misalignment of the book and hence considerable spoilage.
Consequently, book blocks are often piled on skids until dry prior to casing-in, thereby causing delays and requiring additional labor. This process, moreover, brings about another problem. The book blocks towards the bottom of the pile tend to become compressed under the natural weight of the book blocks above. The rollers that apply the glue or paste in the casing-in machine, however, must be adjusted and spaced within close tolerances. Accordingly, the casing-in machine's operator must continually stop the equipment to readjust the rollers. Failure to do so accurately results in excessive adhesive application on the thicker book units (called "creepage"), whereby the overabundant adhesive creeps over the edges of the book block and bonds together several outer pages), or insufficient adhesive application on the thinner book blocks towards the bottom of the pile. Depending upon the shape of the book blocks to be cased-in, as many as three sets of rollers must therefore be continually readjusted. The use of multiple pairs of rollers, moreover, requires the waste of larger quantities of adhesive when the "glue pots" are cleaned at the completion of an operating schedule.
In prior art casing-in, it is often necessary for an operator to realign manually the book block within its case after the two have been pressed together. Misalignment occurs frequently because of the abrupt, starting-and-stopping movements inherent in the equipment. In addition to the extra labor required, in some cases the misalignment is so severe that the book block and case must be separated by hand and reprocessed. Before recycling, however, the book block must be allowed to dry to prevent adhesive from fouling the equipment's mechanisms.
In casing-in very thin "juvenile" books (under 1/4-inch thick), automatic book block feeding equipment cannot be used. Book blocks must accordingly be manually and individually positioned on the wing by one operator, and a second operator removes the book block-with-case from the wing after processing. Operating speed is therefore limited by both operator's dexterity.